Preheat your waffle iron according to the manufacturer's instructions, or to 400°F (200ºC) if your waffle maker has a temperature gauge.
Mix 2 tablespoons of ground flaxseed with 6 tablespoons of water to make the flax eggs. Let the mixture rest at room temperature for at least 5 minutes.
In a large bowl, whisk together the all-purpose flour, sugar, baking powder, and salt.
Add the flax eggs, non-dairy milk, oil, and vanilla extract to the dry ingredients, and stir with a wooden spoon until JUST combined. Don't over-mix, a few lumps are okay.
Grease the waffle iron with non-stick spray and spoon the batter onto the wells, covering most of them.
Close the lid and avoid opening the waffle maker before the steam has COMPLETELY stopped to ensure evenly cooked waffles.
Notes
Ensure perfect results by heating your waffle iron to the right temperature for even cooking before adding the batter.
To prevent sticking, use a non-stick waffle iron or apply a light coating of cooking spray to the iron.
Overmixing the batter can result in tough and dense waffles. Instead, mix until just combined to create lighter and fluffier waffles.
For fluffier waffles, let the batter rest for a few minutes before cooking to create air pockets in the batter.
For evenly served and warm waffles, keep cooked waffles warm in a low-heat oven while finishing the rest of the batter.